Set initiated area event triggered positioning method in mobile communication system

ABSTRACT

A SET-initiated area event triggered positioning method in a session-based service system is disclosed. The method is variously performed according to a proxy mode or a non-proxy mode, and further according to which SLP (SUPL location platform) has a positioning procedure.

This application is a Continuation Application of co-pending U.S.application Ser. No. 11/783,213 filed on Apr. 6, 2007 and for whichpriority is claimed under 35 U.S.C. §120, which claims priority to U.S.Provisional Application Nos. 60/789,609; 60/795,184; 60/810,631 and60/836,938 filed on Apr. 6, 2006; Apr. 27, 2006; Jun. 5, 2006 and Aug.11, 2006; respectively and Korean Patent Application No. 10-2007-0011577filed on Feb. 5, 2007 in Republic of Korea respectively. The entirecontents of these applications are herein fully incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mobile communication system, and moreparticularly, to a SET-initiated area event triggered positioning methodin a mobile communication system capable of initiating an area eventtriggered session and performing an area event triggered positioningprocedure by a SET in a session-based service system.

2. Description of the Background Art

In a mobile communication system, a function group for calculating aposition estimate of a mobile terminal is provided at a mobilecommunication network, and a location service for informing the positionestimate to an entity periodically or according to a user's request isprovided. The network regarding the location service has variousconfigurations according to inner configurations such as 3GPP or 3GPP2.

A method for calculating a position estimate of a terminal in the mobilecommunication system includes a cell-id method for informing an ID of acell to which a terminal belongs, a triangulation method for calculatinga position estimate of a terminal by using a triangulation aftermeasuring wave sending time from the terminal to each base station, aGPS using method, etc.

In order to provide location service to a user by using the abovemethods, signaling and location information have to be sufficiently sentbetween the terminal and a location server. Accordingly, positioningtechnologies for providing location service, i.e., a location servicebased on a position estimate of the terminal is being spread. Theposition technologies may be provided through a user plane and a controlplane. As a representative of the position technologies through the userplane, a secure user plane location (SUPL) method has been well known.

The SUPL method is efficient in sending location information necessaryto calculate a position estimate of a base station, in which locationassistance information such as a GPS assistance is sent, and a userplane data bearer is used to carry protocols regarding the positioningtechnology between the terminal and a network.

An SUPL network regarding a location service in a positioning systemincludes an SUPL Agent, an SUPL Location Platform (SLP), an SUPL EnabledTerminal (SET), etc. The SUPL Agent indicates a logic service accesspoint using substantially measured location information, and the SLPindicates an SUPL service access point inside a network for accessingnetwork resources so as to obtain location information.

The SET is a device communicating with an SUPL network using an SUPLinterface (i.e., a user terminal of UMTS, a mobile station of GSM, alaptop computer having an IS-95 MS function or a SET function, or aPDA). The SET may be various mobile terminals connected to one anotherthrough a WLAN.

The SET supports procedures defined in an SUPL by being connected to anetwork through a user plane bearer. Herein, a network to which a userhas been originally registered is defined as a Home Network, and anetwork of the user's moving area rather than the Home Network isdefined as a Visited Network. An SLP of the Home Network is defined asan Home-SLP, and an SLP of the Visited Network is defined as a V-SLP(Visited-SLP). When an SUPL procedure is started on the network, an SLPto which an external client is firstly connected is defined as an R-SLP(Requesting SLP). The R-SLP is a logical entity, and may be or may notbe same as the H-SLP. A SET having an object to verify a currentposition estimate is defined as a target SET.

The SLP of the network consists of an SPC (SUPL Positioning Center) forcalculating a position estimate, and an SLC (SUPL Location Center) forperforming roaming, resource management, etc. The SET may calculatelocation information by indirectly communicating with the SPC via theSLC (Proxy mode), or may calculate location information by directlycommunicating with the SPC (Non-proxy mode).

In the related art, even if an SUPL-based immediate positioning methodis disclosed, a SET-initiated area event triggered positioning method inan SUPL-based system is not disclosed.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide aSET-initiated area event triggered positioning method in an SUPL system.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described herein,there is provided a SET-initiated area event triggered positioningmethod in a mobile communication system, comprising: receiving a SESSIONSTART message to start a trigger session from a roaming SET by a firstserver; requesting and obtaining area ids of a specific area for an areaevent triggered positioning from a second server by the first server;sending a SESSION RESPONSE message to the SET; receiving a POS INITmessage from the SET, and sending it to the second server; and receivinga calculated position estimate of the SET from the second server, andsending it to the SET; and receiving a SESSION END message from the SET,and sending it to the second server.

The first server sends the area ids obtained from the second server tothe SET through the SESSION RESPONSE message. The first server is anH-SLP, and the second server is a V-SLP.

According to a second embodiment of the present invention, there isprovided a SET-initiated area event triggered positioning method in amobile communication system, comprising: receiving a SESSION STARTmessage to start a trigger session from a roaming SET by a first server;requesting and obtaining area ids of a specific area for an area eventtriggered positioning from a second server by the first server; sendinga SESSION RESPONSE message to the SET; performing a positioningprocedure with the SET by the first server, and sending a calculatedposition estimate of the SET to the SET; and receiving a SESSION ENDmessage from the SET.

The first server sends the area ids obtained from the second server tothe SET through the SESSION RESPONSE message. The first server uses aproxy mode, and has a positioning function to calculate a positionestimate of the SET.

According to a third embodiment of the present invention, there isprovided a SET-initiated area event triggered positioning method in amobile communication system, comprising: sending a SESSION START messageto start a trigger session to a first server by a SET; receiving aSESSION RESPONSE message from the first server; sending a POS INITmessage to the first server; receiving a calculated position estimate ofthe SET from the first server; checking if an event trigger conditionhas been met by comparing the calculated position estimate with positionvalues of an event area; and if the event trigger condition has beenmet, providing the calculated position estimate by the SET to its agent.

The SET receives the area ids of the event area from the first serverthrough the SESSION RESPONSE message. The area ids are obtained from thesecond server by the first server, and the first serer uses a proxymode.

According to a fourth embodiment of the present invention, there isprovided a SET-initiated area event triggered positioning method in amobile communication system, comprising: receiving a SESSION STARTmessage to start a trigger session from a roaming SET by a first server;requesting and obtaining area ids of a specific area for an area eventtriggered positioning from a third server via a second server by thefirst server; sending a SESSION RESPONSE message including at least anaddress of the third server and parameters about a security sessionestablishment to the SET; and receiving a SESSION END message from thethird server by the first server.

The first server sends the obtained area ids to the SET through theSESSION RESPONSE message. The first server uses a non-proxy mode, andthe third server performs a positioning function. Herein, the firstserver is an H-SLC, the second server is a V-SLC, and the third serveris a V-SPC.

According to a fifth embodiment of the present invention, there isprovided a SET-initiated area event triggered positioning method in amobile communication system, comprising: sending a SESSION START messageto start a trigger session to a first server by a SET; receiving fromthe first server a SESSION RESPONSE message including at leastparameters about a security session and an address of a second server;sending a POS INIT message to the second server by the SET; performing apositioning procedure by the SET by establishing a security session withthe second server by using the parameters; receiving a calculatedposition estimate of the SET from the second server; checking by the SETif an area event trigger condition has been met by comparing thecalculated position estimate with position values of an event area; andif the area event trigger condition is met, providing the calculatedposition estimate by the SET to its agent.

The SET receives the area ids covering the event area from the firstserver through the SESSION RESPONSE message.

The first server may provide the area ids obtained from the secondserver to the SET through a third server. Herein, the first server is anH-SLC, the second server is a V-SPC, and the third server is a V-SLC.

The first server may provide the area ids obtained from the third serverto the SET. Herein, the first server is an H-SLC, the second server is aH-SPC, and the third server is a V-SLC.

According to a sixth embodiment of the present invention, there isprovided a SET-initiated area event triggered positioning method in amobile communication system, comprising: receiving a SESSION STARTmessage to start a trigger session from a SET by a first server;requesting and obtaining area ids for an event area from a second serverby the first server; sending a SESSION RESPONSE message including atleast parameters about a security session establishment and an addressof the third server to the SET by the first server; and receiving aSESSION END message from the SET through the third server by the firstserver.

The first server sends the obtained area ids to the SET through theSESSION RESPONSE message. Herein, the first server is an H-SLC, thesecond server is a V-SLC, and the third server is an H-SPC.

According to an embodiment, the invention provides a SUPL EnabledTerminal (SET)-initiated area event triggered positioning method in amobile communication system having a home network and a visited networkthat support roaming of the SET, the method comprising: receiving, by afirst server, a SUPL TRIGGERED START message from a SET to start atrigger session, the SUPL TRIGGERED START message including asession-id, SET capabilities, a trigger type indicator, a locationidentifier (lid), and trigger parameters; verifying, by the firstserver, whether the SET is roaming; sending, by the first server, a RLPSSRLIR message that includes the SUPL TRIGGERED START message to asecond server after the SET is verified to be roaming; sending, by thesecond server, a RLP message to the first server, the RLP messageincluding area ids to a specific area in the trigger parameters;sending, by the first server, in response to the SUPL TRIGGERED STARTmessage, a SUPL TRIGGERED RESPONSE message to the SET, the SUPLTRIGGERED RESPONSE message including a session-id, a positioning method,and area ids corresponding to the specific area; receiving, by a thirdserver from the SET, a POS INIT message to allow the SET to start apositioning session with the third server when a comparison of a currentcell-id and one of the area ids satisfy a positioning session startcondition, wherein the POS INIT message includes a session-id, lid, andSET capabilities; calculating, by the third server with the SET, apositioning result by exchanging positioning messages; sending, by thethird server to the SET, a SUPL REPORT message that includes thepositioning result; and receiving, by the third server from the SET, aSUPL END message.

According to an embodiment, the invention provides a SET-initiated areaevent triggered positioning method in a mobile communication systemhaving a home network and a visited network that support roaming of theSET, the method comprising: sending, to a first server, a SUPL TRIGGEREDSTART message to start a trigger session, the SUPL TRIGGERED STARTmessage including a session-id, SET capabilities, a trigger typeindicator, a location identifier (lid), and trigger parameters;receiving, from the first server in response to the sent SUPL TRIGGEREDSTART message, the SUPL TRIGGERED RESPONSE message to the SET, the SUPLTRIGGERED RESPONSE message including a session-id, a positioning method,and the area ids corresponding to the specific area; sending, to a thirdserver, a POS INIT message to start a positioning session with the thirdserver when a current cell-id and one of the area ids correspond to eachother, wherein the POS INIT message includes a session-id, lid, and SETcapabilities, and wherein the first server receives the area ids of thespecific area from the third server through a second server; performingthe positioning session with the third server by exchanging positioningmessages with the third server to obtain a positioning result;receiving, from the third server, a SUPL REPORT message including thepositioning result; comparing the positioning result with the specificarea in the trigger parameters; and reporting, to a SUPL Agent, thepositioning result when a trigger condition in the trigger parameters issatisfied.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a view showing a SET-initiated area event triggeredpositioning method according to a first embodiment of the presentinvention;

FIG. 2 is a view showing a SET-initiated area event triggeredpositioning method according to a second embodiment of the presentinvention;

FIG. 3 is a view showing a SET-initiated area event triggeredpositioning method according to a third embodiment of the presentinvention; and

FIG. 4 is a view showing a SET-initiated area event triggeredpositioning method according to a fourth embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

Hereinafter, preferred embodiments of the present invention will beexplained.

The present invention is implemented in an SUPL network. However, thepresent invention may be applied to a wireless communications systemoperated in any other standard.

The present invention provides a SET-initiated area event triggeredpositioning method in a mobile communication system, in which apositioning procedure for a roaming SET on a visited network (i.e.,entering to a specific area, leaving the specific area or staying at thespecific area) is performed in a session-based positioning system whenthe SET and a server manage trigger information for positioning.

In the area event triggered positioning method according to the presentinvention, a home network requests area ids of a specific area for anarea event triggered positioning to a visited network, obtains the areaids from the visited network and provides the obtained area ids to atarget SET (a roaming SET).

In the area event triggered positioning method according to the presentinvention, a positioning procedure for the SET is not always performedbut is performed only when the SET is positioned near a specific area(“the specific area” can be referred as a requested area or an eventarea). The SET determines whether to start a positioning procedureaccording to whether a positioning starting condition has been met. Thefact that a positioning starting condition has been met indicates thatthe SET has been approached to an area specified in the area eventtrigger condition information (a specific area, a requested area, or anevent area).

If a calculated position estimate of the SET belongs to the event area(i.e., if the area event trigger condition has been met), the SET judgesthat an area event has occurred. Then, the SET sends the calculatedposition estimate to a client (a terminal, or an agent included in anetwork).

An area event occurrence indicates that the SET enters into the eventarea, leaves the event area, or stays at the specific area.

A location service provided from an SUPL-based positioning system isdivided into a network-initiated case and a SET-initiated case.

The SUPL-based location service is divided into a proxy mode and anon-proxy mode. According to the proxy mode, a positioning procedurebetween a location server and a SET is performed via an H-SLP of a homenetwork operated as a proxy. According to the non-proxy mode, thepositioning procedure between the location server and the SET isdirectly performed not via the H-SLP (or H-SLC) of a home networkoperated as a non-proxy. The location server may be the H-SLP or aV-SLP.

The SUPL-based location service may be classified according to whether apositioning procedure for the SET is performed by the H-SLP (or theH-SPC) or the V-SLP (or the V-SPC).

In the present invention, four preferred embodiments will be explainedaccording to whether a proxy mode has been applied to a SET-initiatedcase, or according to whether a location server belongs to an SLP onwhich network.

Hereinafter, a SET-Initiated area event triggered positioning methodaccording to a first embodiment of the present invention will beexplained.

FIG. 1 is a view showing a SET-initiated area event triggeredpositioning method according to a first embodiment of the presentinvention, in which a roaming case, a SET-initiated case, a V-SLPpositioning case and a proxy mode are implemented. Referring to FIG. 1,the SET is a roaming SET, the SET initiates an area event triggeredservice, the V-SLP performs a positioning function (i.e., is operated asa location server), and the H-SLP uses a proxy mode.

As shown in FIG. 1, the SUPL Agent in the SET receives a request for anarea event triggered service from an application running on the SET. TheSET attaches itself to a packet data network if it is not alreadyattached thereto, or establishes a circuit switched data connection(S90).

The SUPL Agent in the SET uses a default address provisioned by a HomeNetwork to establish a secure IP connection to the H-SLC, and sends anSUPL TRIGGERED START message to start a positioning session with theH-SLP (S91).

The SUPL TRIGGERED START message contains at least a session-id, SETcapabilities, a trigger type indicator (e.g., an area event), a locationidentifier (lid), SET capabilities, and trigger parameters.

As the SET sends an SUPL INIT message including the trigger typeindicator to the H-SLP, the H-SLP recognizes that the area event triggerpositioning is currently requested.

The lid indicates an id of a cell to which the SET currently belongs.

The trigger parameters represent an area event triggered parameters.

The trigger parameters may comprise trigger condition information, i.e.,a change-area type for an area event triggered positioning (entering toa specific area, leaving the specific area or staying at the specificarea) and the specific area (name or position values of the specificarea).

The H-SLP having received the SUPL TRIGGERED START message verifieswhether the SET is currently SUPL roaming based on routing information(S92). If the SET is SUPL roaming, the H-SLP determines a V-SLP based ona lid contained in the SUPL TRIGGERED START message. The H-SLP sends aroaming location protocol (RLP) triggered standard roaming locationreporting request (TSRLRR) message including the SUPL TRIGGERED STARTmessage to the V-SLP so as to inform the determined V-SLP that the SEThas initialized an SUPL positioning procedure.

The H-SLP has to include an area ids request indicator to the SUPLTRIGGERED START message (S93).

The H-SLP requests an area id for an area event trigger session from theV-SLP by sending the RLP TSRLRR message to the V-SLP.

Once receiving the RLP TSRLRR message, the V-SLP determines a posmethod(positioning method) for an area event triggered session from a SETcapability included in the RLP TSRLRR message. Then, the V-SLP sends anRLP TSRLRA (triggered standard roaming location reporting answer)message to the H-SLP, which informs the H-SLP that an area eventtriggered session has been prepared.

The V-SLP also checks the area ids request indicator included in the RLPTSRLRR message. If area ids are requested by the H-SLP, the V-SLPincludes area ids corresponding to the specific area for an eventtriggered session in the SUPL TRIGGERED RESPONSE message, and then sendsthe RLP TSRLRA message including the SUPL TRIGGERED RESPONSE message tothe H-SLP (S94).

The H-SLP forwards the received SUPL TRIGGERED RESPONSE message to theSET (S95). The SUPL TRIGGERED RESPONSE message should not include anaddress of the H-SLP so as to inform the SET that a new connection shallnot be established.

The SUPL TRIGGERED RESPONSE message includes a posmethod. The SUPLTRIGGERED RESPONSE message may also include area ids for an area eventtriggered session. Preferably, the area ids represent ids of cells thatbelong to an area that has been requested to be positioned by the SUPLAgent, mobile country codes (MCC), mobile network codes (MNC) orlocation area codes (LAC), or a primary scrambling code number. In caseof a WCDMA, the area id represents a primary scrambling code number.

Then, the SET may release the IP connection with the H-SLP.

Once the area id or the area ids are received through the SUPL TRIGGERRESPONSE message, the SET checks if a positioning session startcondition has been met.

The checking may be performed by comparing a current area id of the SETwith area ids received from the H-SLP.

That is, the SET compares the current area id with the received areaids, and checks if there exists a consistent area id therebetween.

If the change_area type in the trigger parameter (trigger_params)indicates that the SET is verified to enter to the specific area or tostay at the specific area, the SET starts a positioning session when atleast one of the received area ids is consistent with the current areaid. When the at least one of the received area ids is consistent withthe current area id, the SET judges that the positioning session startcondition has been met.

On the contrary, if the change_area type indicates that the SET isverified to leave the specific area, the SET judges that the positioningsession start condition has been met when any one of the received areaids is not consistent with the current area id.

The comparison of the current area id with the received area ids or thearea event trigger in the SET indicates that a position fix has to becalculated. That is, the SET has to check whether itself has approachedto the specific area requested by the SUPL Agent by verifying its coarseposition estimate. Accordingly, a position estimate (or a position fix)of the SET is not always calculated, but is calculated only when it isjudged that the SET has approached to the specific area requested by theSUPL Agent.

If it is judged that the positioning session start condition has beenmet by comparing the area ids with the current area id, the SETrecognizes that itself has approached to the requested area, and startsa positioning session by sending an SUPL POS INIT message to the H-SLP(S96). The SUPL POS INIT message includes at least a session-id and acurrent area id of the SET. If the SET has not established a circuitswitched data connection, it attaches itself to a packet data network,and sends the SUPL POS INIT message to the H-SLP so as to start apositioning session with the V-SLP.

The H-SLP operated as a proxy forwards the received SUPL POS INITmessage to the V-SLP that performs a positioning function in an RLP SSRPmessage (S97).

If a position estimate calculated based on information included in theRLP SSRP message (e.g., a cell-id) satisfies a requested QoP, the V-SLPhaving received the RLP SSRP message may directly perform step S99 notvia step S98. On the contrary, if the calculated position estimate hasnot met the requested QoP, step S98 is directly performed. In step S98of FIG. 1, cell-id based positioning methods are not used.

As the SET and the V-SLP exchange successive positioning messagesthrough the H-SLP, the position estimate of the SET is calculated (S98).Preferably, the messages exchanged between the V-SLP and the SET includea session-id, a positioning protocol (RRLP, RRC or TIA-801), etc. TheV-SLP calculates the position estimate based on positioning measurementsreceived from the SET (SET-assisted mode), or the SET calculates theposition estimate based on assistance data obtained from the V-SLP(SET-based mode). Referring to FIG. 1 showing the SET-assisted mode, theV-SLP sends the calculated position estimate (posresult) to the SETthrough an SUPL REPORT message via the H-SLP (S99, S100). In case of theSET-based mode, the SUPL REPORT message is not required.

Once the position estimate (posresult) of the SET is received from theV-SLP through the H-SLP, the SET checks if an area event triggeredcondition has been met, that is, an area event has occurred by comparingthe calculated position estimate with position values of the specificarea defined in the trigger parameter.

If the calculated position estimate is not consistent with the positionvalues of the specific area defined in the trigger parameter, the SETjudges that an area event trigger condition has not been met (i.e., anarea event has not occurred) (S101), and proceed to step S102 thus tore-send the SUPL POS INIT message to the V-SLP through the H-SLP (S102,S103). If the area event has not occurred, steps S102 to S107 and stepsS108 to S113, etc. may be repeatedly performed. FIG. 1 shows steps S96to S107 are repeatedly performed so as to calculate a substantialposition estimate of the SET when the positioning session startcondition has been met or the area event has not occurred.

However, if the calculated position estimate of the SET is consistentwith at least one of the position values for the specific area (i.e., anarea event has occurred) (S101), the SET directly performs step S114 notvia steps S102 to S113 thus to send the calculated position estimate ofthe SET to the SUPL Agent on the SET (S114).

If the calculated position estimate of the SET received from the H-SLPthrough step S112 is consistent with the event area (i.e., if area eventhas occurred), the SET sends the calculated position estimate of the SETto the SUPL Agent on the SET (S114).

Then, the SET sends the SUPL END message to the H-SLP, and the H-SLPsends the SUPL END message to the V-SLP in an RLP SSRP tunnel messagethus to inform that the triggered session has been completed (S115,S116).

Then, the SET and the V-SLP release all resources regarding thepositioning session.

As shown in FIG. 1, when the SET-initiates an area event triggeredservice, the H-SLP obtains area ids regarding the area event triggeredsession from the V-SLP thus to provide the area ids to the SET. If apositioning session start condition to calculate a substantial positionestimate of the SET is met, the SET and the V-SLP establish apositioning session through the H-SLP operated as a proxy, andcalculates a substantial position estimate of the SET. If it is judgedthat an area event has occurred based on the calculated positionestimate of the SET, the SET sends an SUPL END message to the H-SLP thusto end the positioning session.

A SET-initiated area event triggered positioning method according to asecond embodiment of the present invention will be explained.

FIG. 2 is a view showing a SET-initiated area event triggeredpositioning method according to a second embodiment of the presentinvention;

As shown in FIG. 2, a roaming case, a SET-initiated case, an H-SLPpositioning case and a proxy mode are implemented.

The second embodiment is different from the first embodiment in that apositioning function to calculate a position estimate of the SET isperformed by the H-SLP not by the V-SLP.

In order to calculate a substantial position estimate of the SET bysatisfying the positioning session start condition (i.e., by verifying acoarse position estimate of the SET), the SET establishes a positioningsession with the H-SLP having a positioning function thus to calculate asubstantial position estimate of the SET itself.

When the SET that has roamed to the V-SLP initiates its locationservice, a positioning procedure to calculate a substantial positionestimate of the SET may be performed through the V-SLP (the firstembodiment), or may be performed through the H-SLP (the secondembodiment).

A SET-initiated area event triggered positioning method according to athird embodiment of the present invention will be explained.

FIG. 3 is a view showing a SET-initiated area event triggeredpositioning method according to a third embodiment of the presentinvention, in which a roaming case, a SET-initiated case, a V-SLPpositioning case and a non-proxy mode are implemented. That is, the SET(target SET) is a roaming SET and initiates a location service, theV-SLP performs a positioning function, and the H-SLP uses a non-proxymode.

The V-SLP includes a V-SLC and a V-SPC, and the H-SLP includes an H-SLCand an H-SPC.

The third embodiment is different from the first embodiment in that apositioning procedure is performed by directly establishing apositioning session between the V-SPC and the SET not via the H-SLC.

The difference between the third embodiment and the first embodimentwill be explained in more detail.

Once the SET sends to the H-SLC an SUPL TRIGGERED START messageincluding a session-id, a trigger type indicator (e.g., an area event),a lid, SET capabilities, and trigger parameters (S122), the H-SLCverifies whether the SET is a roaming SET based on routing information(S122). If the SET is a roaming SET, the H-SLC requests and obtains areaids of the specific area defined by the area event triggered sessionfrom the V-SPC through the V-SLC (S123 to S127).

The H-SLC sends an SUPL TRIGGERED RESPONSE message to the SET (S128).The SUPL TRIGGERED RESPONSE message includes a session-id, a posmethod,a V-SPC address, area ids, a SET auth-key, and a key-id 4. The V-SPCaddress indicates an address to be connected by the SET for apositioning session establishment. The SET auth-key and the key-id 4 areparameters to be served for a security session establishment when adirect session is established between the SET and the V-SPC without aproxy server. The SET accesses to the V-SPC address, and recognizes thata security session should be established by using the SET auth-key andthe key-id 4.

Once the positioning session start condition is met, the SET sends anSUPL POS INIT message to start a positioning session to the V-SPC. Then,the V-SPC and the SET perform a positioning procedure thus to calculatea substantial position estimate of the SET (S129 to S131).

The SET checks if an area event has occurred by verifying whether thecalculated position estimate of the SET meets the area event triggeredcondition (S132).

If the area event has not occurred, steps S133 to S136 are repeatedlyperformed.

On the contrary, if the area event has occurred, the SET sends thecalculated position estimate to the SUPL Agent on the SET (S141), andsends the SUPL END message to the V-SPC thus to release the triggeredsession (S142).

As shown in FIG. 3, when the SET-initiates a location service, the H-SLCobtains area ids of a corresponding area regarding an area eventtriggered session from the V-SPC through the V-SLC, and provides thearea ids to the SET. If a positioning session start condition tocalculate a substantial position estimate of the SET has been met, theSET and the V-SPC establish a direct positioning session without a proxyserver, and a substantial position estimate of the SET is calculated. Ifit is judged that an area event has occurred based on the calculatedposition estimate of the SET, the SET sends an SUPL END message thus toend the positioning session.

A SET-initiated area event triggered positioning method according to afourth embodiment of the present invention will be explained.

FIG. 4 is a view showing a SET-initiated area event triggeredpositioning method according to a fourth embodiment of the presentinvention, in which a roaming case, a SET-initiated case, an H-SLPpositioning case and a non-proxy mode are implemented. That is, the SET(target SET) is a roaming SET and initiates a location service, theH-SLP performs a positioning function, and the H-SLP uses a non-proxymode.

The V-SLP comprises a V-SLC and a V-SPC, the H-SLP comprises an H-SLCand an H-SPC, and the H-SPC performs a positioning function.

The fourth embodiment is different from the first embodiment in that apositioning function to calculate a substantial position estimate of theSET is performed by the H-SLP (in particular, H-SPC), and the H-SLC usesa non-proxy mode.

The difference between the fourth embodiment and the first embodimentwill be explained in more detail.

The H-SLC sends an SUPL TRIGGERED RESPONSE message to the SET withincluding an H-SPC address, a SET auth-key, a key-id 4 parameter, etc.therein (S157).

Since the H-SLC uses a non-proxy mode, the SET auth-key and the key-id 4parameter are used to establish a security session for a positioningprocedure between the H-SPC and the SET. The H-SPC address indicates anaddress of the H-SPC of which positioning session is to be establishedby the SET.

If the positioning session start condition has been met, the SET sendsthe SUPL POS INIT message to the H-SPC (S158). In order to convert a lidincluded in the SUPL POS INIT message (that is, a current cell id of theSET) into a position estimate, the H-SPC requests the conversion of thelid to the V-SLC via the H-SLC (S159-S160). The V-SLC converts (ortranslates) the received lid into the position estimate and returns theresult to the H-SLC in an RLP SRLIA message (S161). The H-SLC forwardsthe position estimate of the SET to the H-SPC through internalcommunication (S162).

The H-SPC checks if the obtained position estimate meets a QoP, andsends an SUPL REPORT message to the SET if so (S164).

However, if the obtained position estimate has not met the QoP, theH-SPC establishes a positioning session with the SET thus to calculate asubstantial position estimate of the SET (S163). Once the substantialposition estimate of the SET is calculated, the H-SPC sends the SUPLREPORT message to the SET thus to forward the calculated positionestimate to the SET (S164).

The SET compares the received calculated position estimate with theposition values of the specific area (the event area) defined by thearea event triggered condition, thereby checking if an area event hasoccurred.

As shown in FIG. 4, when the SET (the roaming SET) initiates a locationservice, the H-SLC obtains area ids of a corresponding area for an areaevent triggered session from the V-SPC through the V-SLC, and providesthe area ids to the SET. If a positioning session start condition tocalculate a substantial position estimate of the SET has been met, theSET and the H-SPC establish a direct positioning session without a proxyserver, and a substantial position estimate of the SET is calculated. Ifit is judged that an area event has occurred based on the calculatedposition estimate of the SET, the SET sends an SUPL END message to theH-SPC thus to end the positioning session.

As aforementioned, in the present invention, since the SET-initiatedpositioning method based on an SUPL is proposed, SUPL-based positioningmethods can be variously implemented.

As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the metes and bounds of theclaims, or equivalents of such metes and bounds are therefore intendedto be embraced by the appended claims.

What is claimed is:
 1. A SUPL (Secure User Plane Location) EnabledTerminal (SET)-initiated area event triggered positioning method in amobile communication system having a home network and a visited networkthat support roaming of the SET having a SUPL Agent, the methodcomprising: receiving, by a first server of the network, a SUPLTRIGGERED START message from a SET to start a trigger session, the SUPLTRIGGERED START message including a session-id, SET capabilities, atrigger type indicator for indicating an area event, a locationidentifier (lid), and trigger parameters, wherein the trigger parametersinclude trigger conditions indicating a change-area type for an areaevent triggered positioning, and an event area indicating a name orposition values of the event area, and wherein the change-area type foran area event triggered positioning indicates entering to the eventarea, leaving the event area, or staying at the event area; verifying,by the first server of the network, whether the SET is roaming; sending,by the first server of the network, a RLP SSRLIR message that includesthe SUPL TRIGGERED START message to a second server after the SET isverified to be roaming; sending, by the second server, a RLP message tothe first server, the RLP message including area ids that represent idsof cells that belong to an area that has been requested to be positionedby the SET; sending, by the first server, in response to the SUPLTRIGGERED START message, a SUPL TRIGGERED RESPONSE message to the SET,the SUPL TRIGGERED RESPONSE message including a session-id, apositioning method, and the area ids; receiving, by a third server fromthe SET, a POS INIT message to allow the SET to start a positioningsession with the third server when a comparison of a current area-id andone of the area ids satisfies a positioning session start condition,wherein the POS INIT message includes a session-id, lid, and SETcapabilities; calculating, by the third server with the SET, apositioning result by exchanging positioning messages; sending, by thethird server to the SET, a SUPL REPORT message that includes thepositioning result, whereby the SET then checks whether at least one ofthe trigger conditions included in the trigger parameters has beensatisfied, based on a result of comparing the calculated positioningresult with the at least one of the trigger conditions included in thetrigger parameters for the area event triggered positioning with respectto the entering, leaving, or staying at the event area indicated by thechange-area type; and receiving, by the third server from the SET, aSUPL END message, wherein the first server is a H-SLP (Home SUPLLocation Platform), the second server is a V-SLC (Visited SUPL LocationCenter), and the third server is a V-SPC (Visited SUPL PositioningCenter), and wherein the trigger parameters include the area ids thatrepresent one of ids of cells that belong to mobile country codes (MCC)and primary scrambling code numbers.
 2. The method of claim 1, whereinthe trigger type indicator is an area event.
 3. The method of claim 1,wherein the verifying step is based on routing information.
 4. Themethod of claim 1, wherein the trigger parameters further include thearea ids that represent one of ids of cells that belong to an eventarea, mobile network codes (MNC), and location area codes (LAC).
 5. ASUPL (Secure User Plane Location) Enabled Terminal (SET)-initiated areaevent triggered positioning method in a mobile communication systemhaving a home network and a visited network that support roaming of theSET having a SUPL Agent, the method comprising: sending, to a firstserver, a SUPL TRIGGERED START message to start a trigger session, theSUPL TRIGGERED START message including a session-id, SET capabilities, atrigger type indicator for indicating an area event, a locationidentifier (lid), and trigger parameters, wherein the trigger parametersinclude trigger conditions indicating a change-area type for an areaevent triggered positioning, and an event area indicating a name orposition values of the event area, and wherein the change-area type foran area event triggered positioning indicates entering to the eventarea, leaving the event area, or staying at the event area; receiving,from the first server in response to the sent SUPL TRIGGERED STARTmessage, the SUPL TRIGGERED RESPONSE message to the SET, the SUPLTRIGGERED RESPONSE message including a session-id, a positioning method,and area ids that represent ids of cells that belong to an area that hasbeen requested to be positioned by the SET; sending, to a third server,a POS INIT message to start a positioning session with the third serverwhen a current area-id and one of the area ids correspond to each other,wherein the POS INIT message includes a session-id, lid, and SETcapabilities, and wherein the first server receives the area ids of theevent area from the third server through a second server; performing thepositioning session with the third server by exchanging positioningmessages with the third server to obtain a positioning result;receiving, from the third server, the SUPL REPORT message includes thepositioning result; comparing the positioning result with at least oneof the trigger conditions included in the trigger parameters for thearea event triggered positioning with respect to the entering, leaving,or staying at the event area indicated by the change-area type; andreporting, to the SET, the positioning result when a trigger conditionin the trigger parameters is satisfied as a result of the comparingstep, wherein the first server is a H-SLP (Home SUPL Location Platform),the second server is a V-SLC (Visited SUPL Location Center), and thethird server is a V-SPC (Visited SUPL Positioning Center), and whereinthe trigger parameters include the area ids that represent one of ids ofcells that belong to mobile country codes (MCC) and primary scramblingcode numbers.
 6. The method of claim 5, wherein the calculating of thepositioning result is performed by the V-SPC if SET-assisted modeexists, or is performed by the SET if SET-based mode exists.
 7. Themethod of claim 1, wherein the trigger type indicator and the triggerparameters included in the SUPL TRIGGERED START message are separate anddifferent parameters from each other.
 8. The method of claim 1, whereinthe trigger type indicator and the trigger parameters additionallyincluded in the SUPL TRIGGERED START message are separate and differentparameters from the session-id, the SET capabilities, and the lidincluded in the SUPL TRIGGERED START message.
 9. The method of claim 5,wherein the trigger type indicator and the trigger parameters includedin the SUPL TRIGGERED START message are separate and differentparameters from each other.
 10. The method of claim 5, wherein thetrigger type indicator and the trigger parameters additionally includedin the SUPL TRIGGERED START message are separate and differentparameters from the session-id, the SET capabilities, and the lidincluded in the SUPL TRIGGERED START message.